# The Effect of Trigger-to-Retrieval Time Interval on Assisted Reproductive Technology Outcomes in Patients with Poor Ovarian Response: The Effect of Trigger-to-Retrieval Time Interval on Assisted Reproductive Technology Outcomes

## TL;DR

This study finds that retrieving oocytes 34 hours after a trigger improves ART outcomes in patients with poor ovarian response compared to 36 hours.

## Contribution

The study demonstrates that a shorter trigger-to-retrieval interval improves fertilization and embryo quality in poor ovarian responders.

## Key findings

- The 34-hour group had higher oocyte retrieval, maturity, and fertilization rates.
- The 34-hour group produced more high-quality embryos and better pregnancy outcomes.
- Adjusting for AFC confirmed significant differences except for fertilization rate.

## Abstract

The timing of oocyte retrieval after the oocyte maturation trigger is a
critical factor influencing the clinical outcomes of assisted reproductive
technologies (ART). This study examined how different time intervals of 34
and 36 hours between trigger administration and oocyte pickup (OPU)
influence on ART outcomes in patients with poor ovarian response (POR).

This prospective randomized controlled study enrolled 217 women undergoing
intracytoplasmic sperm injection (ICSI) cycles between April 2024 and March
2025. All participants received a GnRH antagonist protocol, followed by a
dual trigger for final oocyte maturation. The cycles were stratified into
two groups based on the time interval between trigger administration and OPU
at 34 and 36 hours. Comparative analyses were conducted to evaluate the
outcomes between the two groups.

Throughout the trial, no significant statistical differences were observed
between the intervention and control groups concerning baseline clinical and
demographic characteristics, except for the antral follicle count (AFC) at
baseline. The findings revealed that the 34-hour OPU group exhibited a
significantly higher number of retrieved oocytes, oocyte maturity rate,
fertilization rate, and number of high-quality embryos compared to the
36-hour group (P0.05). Furthermore, pregnancy outcomes were most favorable
in the 34-hour group (P0.05). After adjusting for AFC, all observed
differences remained statistically significant, with the exception of the
fertilization rate.

Our findings suggest that in POR patients, a 34-hour OPU interval with dual
triggering significantly improves fertilization rates, embryo quality,
biochemical and chemical pregnancy rates compared to 36 hours. This timing
adjustment may enhance oocyte maturation and optimize ART success rates.